Cross-linking using

Laboratory tests indicated that gamma radiation treatment and cross-linking using triaHylcyanurate or acetylene produced a flexible recycled plastic from mixtures of polyethylene, polypropylene, general-purpose polystyrene, and high impact grade PS (62). 

Manufactured PVDF parts can be cross-linked using high energy radiation to produce high temperature wire insulation, and heat-shrinkable tubing or film. 

SiHcone mbber has a three-dimensional network stmcture caused by cross-linking of polydimethyl siloxane chains. Three reaction types are predominantiy employed for the formation of siHcone networks (155) peroxide-induced free-radical processes, hydrosdylation addition cure, and condensation cure. SiHcones have also been cross-linked using radiation to produce free radicals or to induce photoinitiated reactions. 

The maximal flow rates and operational pressures that can be used with Sephadex G types depend primarily on the concentration of dextran and the degree of cross-linking used to stabilize the particle. Sephadex G-10, G-15, G-25, and G-50 are quite highly cross-linked, and the first three types are consid-... 

When the polymers are cross linked using borax, you get the children s toy Slime. 

FIGURE 9.11 Relative mass change as a result of water absorption and loss in a solid piece of recombinant resilin prepared from a 20% protein solution in phosphate-buffered sahne (PBS), cross-linked using peroxidase (see [29] supplementary material). The fuUy swollen sample is designated 100. (Data courtesy of Shekibi, Y., Naim, K., Bastow, T.J., and HiU, A.J., The states of water in a protein based hydrogel. Internal CSIRO... 

Fig. 7.6 TEM (A, B) and SEM (C, D) images of NPP-lysozyme prepared using8000 Da PAAasthe bridging molecule. (Image Bis from an ultramicrotomed sample.) The lysozyme/PAA was cross-linked using EDC, after which the MS template was decomposed using HF/NH4F at pH 5. (Adapted from [98] with permission of Wiley-VCH).

Plot (7 x - TA) as a function of cross-linking using DiBencdetto s equation for poly(l,4-buladicnc) and for polystyrene. 

PVA has also been extensively used for immobilization of biocatalysts in a membranous form. As compared to PAAm, PVA is more hydrophilic and having adhesive property with better tensile strength in dry conditions. But it has high swelling index and dissolves readily in water when not cross-linked. PVA can be cross-linked using a variety of reagents including... 

Spoly(vinylbenzylchloride). -Cross-linked using divinylbenzene. Chloromethylated, cross-linked polystyrene resins were obtained coiranercielly from Bio-Rad Laboratories. Percent chloromethylation js based on the available phenyl groups in the polymer that is minus the percent cross-linking. =D=dioxane E ethanol. Percent of available chloromethyl croups reacted with donor. —Percent reaction x percent chloromethylation. Polymer prepared by free-radical polymerization of 60.00 para-neta chloromethylated sytrene (Dow Chemical). Reaction heated at 50-55°C. 

Grafting and networking may modify the mechanical, chemical, and functional properties of polymers and enhance their utilization for some purposes, such as for water treatment (Kumar and Verma, 2007 Mishra et al., 2003). Psyllium derivatives were prepared by grafting acrylonitrile onto psyllium molecules using a ceric ammonium nitrate and nitric acid system (Mishra et al., 2003). The resulted grafted psyllium samples were not soluble in commonly used solvents or their combinations. In 2007, methacrylic acid derivatives of psyllium were prepared using ammonium persulfate as initiator and cross-linked using N,N-methylenebisacryla-mide as the crosslinker (Kumar and Verma, 2007). The modified psyllium... 

These steps are typical for most of the synthetic elastomers. The use of sulfur for vulcanization is common for the production of most elastomers. Magnesium and zinc oxides are often used for the cross-linking of polychloroprene (CR). Saturated materials such as EPM and fluoroelastomers are cross-linked using typical organic cross-linking agents such as peroxides. 

Thermoplastic elastomers based on polyolefins (TPO) are blends of PE or PP wifh EPDM elastomers wherein the elastomer is often cross-linked using thermochemical systems. TPOs more suitable for medical producfs with no chemical residuals can be made using EB processing to cross-link the elastomer portion in such an elastomer-plastic blend. The thermoplastic governs the melt transition, and thus the extrusion properties of TPOs. The radiahon response of these materials is also governed by the choice of fhe thermoplastic. An example of an EB cured blend of EPDM and polyefhylene used is for fluid transmission tubing and electrical insulation. ... 

Electron beam processing of solvenf-free liquid systems for coatings, inks, and paints involves essentially polymerizahon and cross-linking using electrons with energies between 120 and 300 keV. Initiation by electrons leads primarily to free radical reactions. Cationic polymerization is only found in rare cases. ... 

The most common compound for peroxide cross-linking of PE in the wire and cable industry is dicumyl peroxide (DCP), which decomposes at 120-125°C (248-257°F), generating free radicals needed for the process plus by-products (carbinol, acetophenone, and methane). The production line for continuous vulcanization of wire and cables by peroxide must be about 200 m (61 ft) long. 2 The plant space required for radiation cross-linking using... 

Thermosetting composites are cured at either ambient or elevated temperatures to obtain a hard solid by cross-linking. Using radiation cross-linking decreases the cure time considerably. In particular, EB has been used in many instances successfully. For example, glass fiber-reinforced composites cured by EB have been used for the production of cladding panels.121... 

Cross-linking using diazonium compounds usually creates deeply colored products characteristic of the diazo bonds. Occasionally, the conjugated molecules may turn dark brown or even black. The diazo linkages are reversible by addition of 0.1 M sodium dithionite in 0.2 M sodium borate, pH 9. On cleavage, the color of the complex is lost. 

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